The Slithery Child of The Crescent Moon
by Alithea Korogane
Summary: (Next Gen AU) "Koro-sensei's legacy has been passed, but not in a way the Class E has been expecting." Seven years have passed since Koro-sensei had faded away in the world, but the now adult Nagisa, Kayano and the E-Class are in a surprise when Karasuma called them to come back to their former assassination classroom for a mission: to handle the young son of Koro-sensei and Aguri.
1. The Great News: Koro-sensei Has A Son!

**_A/N: Hello! There will be a re-editing of this chapter because of plot changes, but it is just minor changes._**

**_Flashbacks are in italics._**

* * *

Tadaomi Karasuma, the commander-in-chief working on the Ministry of Defense, had received a shocking news in the wee hours in the morning.

* * *

_"That's impossible, sir. The octopus couldn't have a child, not that I know of. He never told me he has a son when he told us his past."_

* * *

Tadaomi Karasuma couldn't believe what his superiors told him on the phone earlier that day.

* * *

_"It was actually confirmed, Karasuma-san. The child was truly the child of the moon destroyer. We even had a DNA test on the child, it was a match to the deceased target." His superior had replied to his countless questions that was budding in his mind._

_Karasuma had massaged the bridge of his nose has he listened to the speaker in the other line, "But you said that the child couldn't be older than seven. The octopus died nearly 7 years ago. How could this happen?"_

_The speaker had paused before he slowly explained the situation with professionalism, "Yanagisawa Katara-sensei, the respected scientist and inventor who disappeared in the scientific spotlight for seven years, had confessed that her older brother, Yanagisawa Kotarou, had a secret research that he had been working on since the moon incident, that even the target had never knew of. They had created a child using the target's DNA and Yanagisawa-san's fiancée's egg cells to test if the antimatter genes can be passed through generations. It was unethical, to say at a least."_

_"That means...the octopus never knew the existence of the child?" _

_Karasuma has a million questions in his mind, and this is one of them. Koro-sensei had never told anyone that he had a child, even after he had told his back story to them. That means he had died not knowing that Shiro-san, real name Yanagisawa Kotarou, had unethically made a child...the octopus' child with that closest friend of his, who is the former Class E homeroom teacher._

_"Affirmative. The target never knew about it," his superior had sighed__, "Apparently, according to Yanagisawa-sensei herself, her brother had made not only one, but two children on the experiments. Unfortunately, she only escaped with only one child when she decided to whisked the twins away while the laboratory was in chaos after her brother's failure to dispatch the octopus. She raised the boy in secrecy until the boy turned seven years old."_

_"WHAT?!" Karasuma's black eyes had widened at what he had heard. Not only he had found out that there are actually TWO children made by that bastard__ named Yanagisawa Kotarou for experiments. "Does...the boy knew the existence of his twin?"_

_"Unfortunately, she never told the boy about his twin. Yanagisawa Katara-sensei was so devastated that she never had the chance to get the other child away, that she never had the guts to tell the boy," his superior spoke with pity._

_Karasuma shook his head. Of course, he knew the feeling of losing a loved one. He once had a little sister, but she died before she had a chance to grow up into a fine lady. Karasuma was very devastated over her death, he loved his little sister so much, she was his inspiration to become a soldier._

_"I also have to tell you this, Karasuma-san. We also found out that the child sometimes has his...bad moments, according to our observation. In fact, he still has no control over his extraordinary abilities, and we were worried it will cause damage and injury on himself and those around him."_

_The military man's eyebrows were now knitting in frustration. This day is already weirder and weirder in a second. He thought that after the octopus had died, he will never going to deal another incident regarding to him anyway. But no, the octopus's own children will be going to kick it off all again!_

_But Karasuma was still confused about the twins. __"I had still confusions of this, sir. When you said twins, this means the octopus has twin children?"_

_"Negative. According to the documents that the female Yanagisawa-sensei had given to us, his twin sister was technically his half twin sister only. They only shared a birthday and a mother, both actual and surrogate. The girl was actually the daughter of Yanagisawa Kotarou."_

_Now great...That bastard has made a child of his own._

_"So... Why have you called me, Sir? I am sure this is not just about because I am involved with the octopus years ago?"_

_"I know it is a great favor to ask of you, Karasuma-san, but... I need you to contact your former students again. They need to handle this problem as soon as possible. I'll send the files of this case later on."_

_Karasuma had narrowed his eyes once again. Now they had to involve the children, after 7 years. He may be busy right now, but he and his wife Irina still has contact over their students. They were now successful in life in their chosen careers...and the government will need them again...to deal with this once again? Karasuma shook his head, he wanted his former students to live a peaceful life, after what happened years ago._

_"Sir, do we need to assassinate the child, like we had done to the octopus years ago?"_

_"Negative, Karasuma-san. In fact, we need the child alive for science and military purposes. The tentacles implanted on him was a special kind of tentacle cells made from antimatter, and we would like to know the benefits of it so we could use it to our advantage. As the scientists had found out that the child has a low probability of exploding, which the problem with the child's father. Considering the fact that the child was still young and inexperienced in using his powers, we can't do it or we will be criticised by the world once this problem will go out, just like what happened to that octopus. It will be a crisis that we want to be averted. That means... You and your students will take care of the child and teach him to control these powers of his."_

_"What?!" _

_"Karasuma-san, the child has to be taken care of. Don't worry, his growing powers were limited by the device in his neck, invented by Yanagisawa Katara-sensei herself. It was made to limit his powers to avoid damage to himself and others."_

_"But..." He sputtered while he sat down in his chair. Now great..._

_"You know you can't reject this case. This is an order of the higher authorities."_

_Karasuma sighed as he massaged his aching head while his other hand was holding the phone. He can't refuse the order, now he had to deal this problem again._

_"I will be expecting the file and the child in my custody today."_

_The speaker's voice seem to be happier when Karasuma had accepted the mission. "Good. Good luck on this mission, Karasuma-san. You and your students."_

_Then the phone hanged up, as Karasuma looked at the picture of his wife Irina and their little 5 year old daughter, Aimi._

* * *

Karasuma grabbed his phone and had dialed his former student to talk to him. Now the assassination classroom will be reunited once again after many years...for another mission.

"Hello, Nagisa-kun. Bring Kayano-san and let's meet at the former Class E building this afternoon. We had something to discuss..."

* * *

**_A/N: Welcome to my newest fanfic, and this time it will a AU Next Generation Series!_**

**_This story is a next generation AU-ish AC fanfiction featuring the original AC characters...and some OCs, namely Tsukiro Yukimura ("son of the moon", son of Koro-sensei and Aguri through in-vitro fertilization/experimentation) and Aimi Jelavic-Karasuma ("beautiful love", daughter of Tadaomi and Irina)! This idea was born after seeing a comment in a KoroGuri YouTube AMV, and I can't wait to write about it._**

**_There will confusions in this story, but I will try to polish the concept_****_. And oh, there will be plot changes on this._**


	2. Nagisa Shiota Got the Call

_"Sayonara...Koro-sensei."_

* * *

It was a beautiful Saturday, but not for a former Class E student.

In fact, he thought it was just like any other day.

Shiota Nagisa was making a lesson plan for the next day when Karasuma Tadaomi, his former teacher from his Class E days, called him suddenly.

It's not like he was cutting connections with his former classmates and teachers, but he was currently occupied being an intern teacher in Paradise High School, and it is the start of the new school year. This is his first year in internship, but he was apparently assigned to the worst section of that school: the Class 3-5. The class where the delinquents worse than his former classmate Karma, and slacking school girls had been thrown in.

The outcasts, they were called. The lowest of the low.

Nagisa just sighed deeply, it was just like the class he been when he was still in junior high, but three times worse.

As far as he can remember, Class E don't do vandalizing on walls and joining some shady Yakuza-like gangs and fraternities, even Terasaka Ryoma was nothing compared to his current students.

He looks on the roll book beside him, sighing deeply as he pondered on one thing:

He really feels he is like the Koro-sensei 2.0.

Sometimes, he had to avoid these wet balls of paper that his students thrown in his way, and sometimes a real knife came into the mix. Yes, a REAL knife. Thank goodness for assassination training he had in his Class E days, or he will be dead by now.

Yes, he had incorporated Koro-sensei's assassination classroom teaching methods into his own one, but because he was just an ordinary human compared to Koro-sensei.

He chewed in his pen in frustration, looking at the lesson plan with a tired look in his eyes. As much as he wanted to stop making the plans for the incoming lessons amd rest, he did not follow it and he still continued to write them.

As he continued to finish the lesson plan, his phone rang, making him flinch in surprise. It was normal for him to receive calls at this hour, usually his mom was calling everyday at a specific hour to check if her baby boy was okay.

Not that Nagisa had minded it, but he had been living independently ever since he went to college. His mom, on the other hand, was with his dad, now reunited and had rekindled their relationship, enjoying the rest of their married life doing fun or stuff. She had changed, little by little, ever since Koro-sensei helped them, and Nagisa was happy for that change.

But he still used his mother's maiden surname because he feel that the surname Shiota was fitting for his given name.

Nagisa grabbed his phone and checked the Caller ID if who called him.

**_Karasuma Tadaomi-sensei is calling..._**

Nagisa was confused. Why would his former sensei had called him at this hour?

_It must be important_, Nagisa mused as he pressed the answer button.

"Hello?" he greeted politely, as he was intrigued by his former sensei's intentions why he called Nagisa.

The last time he saw Karasuma is on little Aimi's 3rd birthday two years ago, where all the former Class E were invited, that is why he was currently wondering why Karasuma called him in this time.

"Hello, Nagisa-kun. Bring Kayano-san and let us meet at the former Class E building this afternoon. We have something to discuss."

Nagisa narrowed his eyes as he had pondered on Karasuma's words.

Tadaomi Karasuma, forever a military man, had never called any of his students just to say hello. Of course there is an important reason why his former teacher would call him. Unless...

Nagisa pulled the phone away in his ear and positioned it in front of him just to see the glowing screen of the phone. He looked at the time and date of the phone.

_March 12, 20XX_

He widened his eyes as he looked at the date. Of course, it was Koro-sensei's death anniversary, and he had already visited the Class E building the day before, so he could visit the area earlier for he was supposed to be busy today. Of course, he did not expect Karma Akabane to show up though at that time, but it was a nice moment to share and bond with his former buddy.

Nagisa laughed humorlessly. _Yeah, I killed him using my own hands holding the knife_. _It has been a long time, 7 years has passed. How time flies, Koro-sensei...since you left us...since I killed you._

He put his phone back to his ear as his former sensei is still on the other line, "Discuss? Is it about Koro-sensei's death anniversary? You know that I can't go this time, I have already been gone there-"

"No, it isn't about the octopus' death anniversary plans, it can wait for tomorrow. I mean, it is a real government emergency, and I need the former members of the Assassination Classroom, or the former Class 3-E. And considering the fact that you are the one gives the final blow to the octopus and Kayano-san being the sister of Yukimura Aguri-san, I need you two immediately. I will call the others tomorrow," Karasuma had interrupted Nagisa's rambling, making the bluenette stop.

"A real government emergency? And you need us to respond to it? Why?"

Nagisa couldn't believe what his former sensei will say next.

"Because it involves the octopus, Yukimura-san, and Shiro-san's hidden antimatter project."

* * *

After Karasuma ended the call, Nagisa had called Yukimura Akari, known by the Class E family as Kayano Kaede, and by the world as Haruna Mase.

She is a famous actress of her time, a talented acting prodigy that had gained multiple box office hits and shows. Unknown to many people except to her closest friends, she was actually involved in the Koro-sensei incident 7 years ago, when she was still part of Class E. Her sister, Yukimura Aguri, was the former teacher of Class E before Koro-sensei took her place when she died in a lab accident.

"Oh, Nagisa-kun! Um...why do you call me? It h-h-has been a long since yo-you call me!" Akari's cute voice was heard on the phone, and Nagisa couldn't help but blush. Unknown to Akari, Nagisa has a slight crush on her ever since they kissed, but he rather hid it for the sake of her future career.

Nagisa composed himself and replied, blush creeping on his cheeks.

"Um, hi, Kayano-san, I would like you to know if you are free this afternoon?"

"Hmmmm...let me see my schedule," she answered before her voice started to become muffled, probably due to Akari covering her phone's microphone as she asked her manager about her schedule.

Few minutes has passed and Akari's voice finally became clear, "Apparently, I have free time from 12PM to 7PM, because I have to attend a party at 8PM. Why do you ask?"

"Well, Karasuma-sensei called me earlier, he wanted us to go to the Class E building this afternoon. Would you be there?"

"Of course, I have been planning to go to the building today for Koro-sensei's death anniversary along with some of our former classmates," Akari happily replied.

Nagisa smiled as he looked at the window and the view outside. "Okay, send me your current location so I could fetch you. We will go to the Class E building together."

* * *

It was a long trek, but Nagisa and Akari had finally reached at the top of the hill where the Class E building resided.

The building was still a beautiful sight to behold, even after years of unuse. Seven years since the Class E building was bought by them, it was now unoccupied, especially the Class E system was now abolished, and the Kunugigaoka Academy finally shut down. It was rumored that a new management will finally reopen the school after years of closing.

Even though it was a little broken, but it was still usable as it was 7 years ago. Well, a little roof replacement and some little touches will do the trick, and it will be new again.

They walked to the building, where they saw the Karasuma family. Tadaomi was standing stiffly, Irina Jelavic-Karasuma was waving at them, and their little daugther Aimi was poking curiously at a shy raven-haired boy with big glasses dangling on his nose.

The boy has big eyeglasses that is bigger than he was supposed to have. He has long raven hair that reaches his nape, and with long bangs that nearly covered his little nose. Weird, he has something in his neck, and it is like a metal leash from a random laboratory. He has beautiful black eyes tinged with golden orange, just like...

_...just like my sister's dark eyes. They are full of kindness. Even his nose looks like hers. What's going on? _Akari mused.

When Akari finally looked at the boy clearly, she felt a familiar aura around him. It seems like she and the boy are connected.

Nagisa greeted the happy family, "Good afternoon, Bitch-sensei, Karasuma-sensei."

Irina's head formed a little tick mark as she heard the pet name the Class E had given to her, "Nagisa-kun, there are kids infront of you..."

Oblivious to what Akari has been doing, Nagisa looked at the kids and laughed sheepily, "I am sorry, _Irina-sensei_, I slipped up. We are just happy that we saw you once again after many years, am I right, Kayano-san?" he nudged the acting prodigy beside him, but when she never replied, Nagisa looked at Akari with concern.

Akari has a spooked look in her eyes, as her eyes darted on the boy that was poked by one Aimi Karasuma.

"Kayano-san? Are you okay?"

Kayano could only mutter to Karasuma, "Sensei...who is that kid?"

With those words, Nagisa had snapped out of his happy thoughts and stared at the boy. He had finally realized that he had never seen that boy once in his life, but it seems like he is familiar to him like the boy was an old friend.

"Yeah, Sensei...who is this boy?" He asked his former senseis, as Tadaomi coughed while Irina's smile faltered. They all looked at the shy boy, who noticed that the people stared at him and looked away.

"Kayano-san, Nagisa-kun...this boy... is your mission. His name's**_Yukimura Tsukiro_**," Tadaomi introduced the boy to the surprised former members of Class E, "I hate to surprise you but I had to reveal this information... Kayano-san, he is your biological nephew."

* * *

**_A/N: Chapter Two is out!_****_I am so sorry for updated too long! I have a writer's block right now, and I have been interested drawing the characters than making stories about them!_**

**_By the way, Belated Merry Christmas! I know it was too late, but it is better to be late than nothing, right?_**

**_It was implied in this chapter that this happens between the time Nagisa and Karma visited the Class E Classroom (Assassination Classroom The Movie: 365 Days), and the time Kaede and the other Class E cleaned and fixed the whole classroom (Season 2 Episode 25)._**

* * *

**_TRIVIA ABOUT THE FIC:_**

**_The name of the KoroGuri child, Tsukiro/Tsukirou, means "son of the moon" in Japanese, and it was the rare male counterpart of the female name Tsukiko, which is actually Tsukiro Yukimura's original name I thought of._**

* * *

* * *

**_Technically, I made the TSCCM series last March or April, but I just did the story now, so...you can check my drawings of this next gen AU series in my Facebook and Tumblr (Alithea Korogane)._**

* * *

**_I hope you will enjoy this and hope to see you again on the next chapter!_**

**_Blast to the slithery future and beyond!_**

**_~Alithea Korogane~_**


	3. The New Class E Mission: Raising Him

_"Kayano-san, Nagisa-kun...this boy... is your mission. His name's Yukimura Tsukiro," Tadaomi introduced the boy to the surprised former members of Class E, "I hate to surprise you but I had to reveal this information... Kayano-san, he is your biological nephew."_

* * *

Nagisa and Akari can't believe what their former Sensei has revealed to them. This boy, Tsukiro, was Akari's biological nephew?

Irina could feel the dark aura surrounding the four of them, so she called her daughter, who approached her mother with a bright smile on her round face, "Aimi, darling, can you bring Tsukiro-kun out to play? But please, don't get too far, or you will get lost."

Aimi nodded, then grabbed the now red-faced Tsukiro's hand and dragged him away, as she spoke brightly, "Yes, mommy! Come on, Tsuki-kun!"

"Tsuki-kun?" Tadaomi repeated with a questioning look on his face, when the two children were out of the adult's earshot, earning a shrug and a chuckle from Irina.

"You know Aimi-chan, she became closer to a child she only met for the first time, especially to a boy, in a few seconds," Irina spoke, folding her arms," She is a future woman, she is a natural charmer, like me!"

Tadaomi could only mutter "why do I have to marry you?" comment on his wife, smiling a little at his wife's antics before looking at their former students.

Akari shook her head in confusion, "But I only have one sister, and she is dead long time ago. And all that I know, she is not pregnant at that time! And besides that bastard Yanagisawa-san, Aguri-neechan never had a boyfriend that I know of!" she screamed.

Nagisa looked at the boy, who was still blushing from not far away from they were standing, then made a mental image of his former sensei (Yukimura-sensei). He could see the similarities between Aguri and Tsukiro. The boy has similar hair and eye color as Aguri, and it seems that he also inherited the eyebrows and the cute little nose too. And the smile that the boy has, it was just like her. Tsukiro bears an aura that could make people smile and ease around him, just like Aguri had.

But the eye and facial shape, the pale and milky skin, the nearly invisible little freckles that sprinkled the child's nose...Nagisa could deduce that it must be the father who had given his genes to the child.

"Unfortunately, it is not what the DNA test and this file says," Tadaomi had grabbed a file from his jacket and gave it to Nagisa, who received it and opened it. Akari, with shocked eyes, looked at the file. They read the file, staring at the pictures and the descriptions inscribed on it, their eyes widened every passing second.

"I can't believe it...Neechan, she had a child..." Akari can only gasp in disbelief. For seven years...The child had been existing for many years, and they only knew it now? And for Aguri to have a child..it was unsettling for Akari.

"Tsukiro-kun's father is Koro-sensei?!" Nagisa screamed as he stared at the file in disbelief. Akari looked at the paper bearing the information about Tsukiro's parentage and her eyes scanned four photos on it.

One bears little Tsukiro's picture, probably younger than he is now, with a 'test subject, uncontrollable' label on it. He was still wearing his huge glasses, smiling brightly as his raven-orange eyes sparked with wonder. He was wearing a blue shirt with a moon and bunch of stars with scary faces on it. He still have his leash on his pale neck.

One bears Yukimura Aguri's picture, in a lab coat and silly yellow t-shirt bearing a face of the duck on it, with a 'blood mother, egg donor' label on the picture. She was smiling brightly, her raven-orange eyes sparkled with hope. Akari couldn't help but smile a little, _I can see where Tsukiro got his eyes...and his choice of clothes._

One bears Koro-sensei's picture, with a 'current form-blood father, antimatter genes activated' on it. He was wearing his usual graduation robe attire, with a crescent moon necktie of his, a present of Aguri herself.

Lastly, one bears a picture of a handsome young-looking man, with shaggy raven hair that reaches his nape and bangs that reaches his nose, mellow dark eyes that seems to hide some secrets, pale and milky skin, and weird eyebrows. He was wearing a pale blue shirt, more like you had seen in the lab or in a hospital. There was a label 'human form-blood father, antimatter genes not yet activated' on it.

It didn't take a dumb person to connect the lines between the octopus and that young man.

"This was Koro-sensei when he was human?!" Akari and Nagisa couldn't believe their eyes, "He...he was damn handsome!" Akari screamed in disbelief.

Irina laughed as her husband looks miffed, "That damn octopus was right all along. Koro-sensei was handsome back when he was still the greatest assassin in like, ever... but for me, no one can compete my husband's charm," she flirted on her husband, who rolled his dark eyes, "Come to think about it, I think I have met him before, I think I had once flirted with him at one party I had attended back when I was still active as an assassin. But I never thought it was the God of Death, more especially the octopus years back," Irina raised her hands as she laughed lightly. Her husband just sighed.

Nagisa looked at the picture of Tsukiro and the human Koro-sensei, "Well, that bears the similarities. The pale and milky skin, the little freckles, the eye shape, the structure of the face, the hair style...it seems Tsukiro-kun inherited Sensei's good looks," he had commented.

Tadaomi shook his head as he replied, "Not just the octopus' human form's looks that the boy inherited from his father."

Nagisa and Akari got confused, as they both spoke, "What do you mean, Karasuma-sensei?"

The military man had looked at the two children playing afar, most likely Aimi poking the poor little Yukimura Tsukiro. The boy was looking down, his face red with embarrassment. His huge glasses were a little skewed as he try to push it back into place.

"Tsukiro-kun apparently had inherited some of the abilities that his octopus father had. More likely, he can conjure tentacles from any part of his body," the military man had spoke.

"That means that...Tsukiro-kun is like Kayano and Itona-kun before?" Nagisa inquired, earning a guilty look from Akari.

Tadaomi shook his head as he spoke grimly, as he looked at the boy in question, "Unfortunately, Tsukiro-kun's condition is more advanced than the tentacle implants, but less advanced than the octopus' condition. We could say, it is like the tentacle implants, just like in the case of Kayano-san and Itona-kun, but compared to the two, Tsukiro-kun's tentacles can't be easily removed, for the antimatter particles is already grafted in his DNA. In short, it is impossible to eradicate, the tentacles is already part of him."

Akari looked at the children with pity, asking her former Sensei with sadness on her voice, "That means he can't have a normal life? If his tentacles are permanent, does that mean he had to be monitored and experimented for the rest of his life? Do...we need to kill him like we did to Koro-sensei? Maybe that is why you called us, isn't it?"

Nagisa widened his eyes at what he had heard and looked at Tadaomi with disbelief, "Sensei, we can't kill a child!"

Tadaomi sighed, his wife Irina comforted her husband by patting his back with her smooth touch. "You misunderstand. I called you two here first because you two are closer to that octopus, especially Kayano-san being related to Yukimura Aguri-san. The rest of the E-Class will be informed about this too, they are also included in this mission."

The man closed his eyes, and took a deep breath, before he spoke in a serious voice, "You will be tasked to take care of Yukimura Tsukiro and teach him to control these powers of his."

"WHAT?!"

Akari and Nagisa widened their eyes as they couldn't believe what Tadaomi had told them.

Their former Sensei's expression never changed. "In fact, the government need the child alive for science and military purposes, as we have been expected to know. As I said before, Tsukiro is a special case, for his tentacles implanted on him was a special kind of tentacle cells made from antimatter, and they would like to know the benefits of it so the government could use it to their advantage."

Akari narrowed her hazel eyes as she yelled in anger, "Governments and their agendas! Tsukiro-kun is just a damn child! And he is still human! How unethical is this?"

Irina gently lowered her voice as she commented, "Creating the boy is unethical enough, dear."

Tadaomi glared at his wife, "Not the time, Irina."

Irina shrugged, "I am pointing a fact, Omi-chan. We can't deny that Yanagisawa bastard had crossed the line."

Nagisa nodded, as Akari looked at the boy playing with Aimi, "Bitch-sensei is right, he crossed the line by experimenting with life already. But we could not blame the child for just existing."

"What about exploding? Is he like Koro-sensei? An unstable antimatter creature? Will there be a deadline? Please don't tell me he has a deadline..." Akari asked, still looking at the boy with worry.

Tadaomi replied, "Fortunately, they had revealed that the scientists had found out that the child has a low probability of exploding, which the problem with the octopus at first. Apparently, Yanagisawa had replicate the chemical that Okuda-san had made for that octopus."

The two young adults sighed in relief.

"But we had to consider the fact that the child was still young and inexperienced in using his powers, and the government can't raise the child nor kill it, or it will be another Koro-sensei drama again," Karasuma vocalized his concerns, as the two nodded in agreement.

"So...we need to raise the child as a class?" Akari questioned, as she looked at the children.

The former Sensei nodded, "Yes. But don't worry, the government will provide you funds and things needed to raise him. Of course, they will monitor the child's progress every few months so they could see how he had been developed. The boy was on his rough times, so I hope you will do your best to raise him into a respected individual."

The two nodded, "We will not fail you."

Akari stared at the file again as she caressed the photo of her deceased sister, when she noticed another paper stuck below the page full of Tsukiro's info. She grabbed the file from Nagisa as she picked the paper and her eyes scanned the data.

"Twin sister? Tsukiro's other half? What does this mean?" Akari questioned.

"And who is this baby? I am sure it is not Tsukiro-kun, the hair was different. It was dark green," Nagisa pointed out, seeing the photograph attached to it.

The Karasumas looked at each other before turning their heads to their former students, Tadaomi sighed deeply as he spoke, "I forgot to tell you but...Tsukiro-kun is not the only child created by Yanagisawa Kotarou."

Akari and Nagisa's eyes widened in shock.

"In fact, he created another child. His own child."

* * *

In a mysterious place not far away, a 7-year-old girl was crying in the corner of her room. The room is colored pink, with a comfortable bed on the side of the room, and no windows. There were books and educational toys lying around the floor, while a chalkboard has messy mathematical scribbles on it.The door leading to the outside was locked, making her trapped.

The door opened, revealed a blonde man in a lab coat, looking at the child with fake cheerfulness. The child looked up, her green curls was flowing in her head, black tinged with orange eyes were staring at the man fearfully, whimpering.

The man smiled as he approached the trembling child, cold eyes looking at her as he spoke smoothly,

"Well, dear child, it is time..."

* * *

**_A/N: Welcome to the third chapter of The Slithery Child of the Crescent Moon!_**

**_It has been a long time since I have updated this story, and I am happy I did! Apparently, this was actually made months, but just finished it now. Even though I had never updated this, I had made some fan arts about teenage Tsukiro and Aimi and posted it on my FB account, but if you want to check it out, I will post it on my Tumblr (same name as this account_****_). I much prefer to do arts than writing, so I have tons of TsukiAi fanarts. And some of them contains spoilers for this story._**

**_And I did reworks on Chapter One. Originally, I was supposed to let Tsukiro stay in the lab for seven years before he escaped, but I changed it to when he was still a baby, back when the lab is in chaos during the Koro-sensei execution ( S02 E22-24). It will not affect the two chapters, but feel free to read it again if you want._**

**_Also, I had to remind you, while this may be classified as AU because of Tsukiro's existence, I know how the manga and anime series works with its twists and revelations, due to me managing an AC fanpage!_**

**_The ships and OTPs will be canon-based. Sorry for KarmaGisa and KaruShuu fans, no yaoi this time in this story. KarNami and NagiKae will be shown, along with KaraRina and KoroGuri. But we focus on TsukiAi OTP in this story._**

**_And by the way, currently we are on the verge of the pandemic of coronavirus disease 2019, a infectious respiratory illness caused by SARS-COV-2. So to protect yourself, be hygenic. Wash your hands everytime, wear a face mask if needed and be healthy._**

**_And pray for the victims and their families in these difficult times._**

* * *

**_Don't forget to review, favorite and follow this story, I really appreciate the gesture. And oh, if you had interest in reading some of my stories, check my profile!_**

**_I have a crossover story named 'Hidden Within The Mysterious Fob Watch', which is a Doctor Who/Assassination Classroom crossover!_**

**_Check it out!_**

**_With crescent moons and tentacles,_**

**_Alithea Korogane_**


	4. Tsukiro and Aimi's First Meeting

_"Where am I?"_

Little Yukimura Tsukiro lived a complicated life.

The seven-year old looked around as he still adjusted in his new surroundings. It was new to him, as he was always been confined on the four corners of a little house located in the outskirts of Kunugigaoka all his life.

He was located in a small room, where there is a office table on the other side from where he was sitting. Sunlight was filtered by the huge windows, and the table was full of pens, work related papers, a laptop, and a picture frame with a family picture on it.

The room was homely, but Tsukiro was too terrified to be comfortable. His cheeks were stained by tear tracks, as he was utterly terrified at what happened to him now.

* * *

_"Who am I?"_

When he was still little, he would always ask his 'mother', Yanagisawa Katara, if who is his father and why would she never let Tsukiro come out of the house. Katara would just shrugged it off or tell him that his father was now in a better place and had always watched over him.

As a inquisitive young child, little Tsukiro always wonders what lies behind the door that leads outside. The house has windows, yes, but it was always covered in blinds, and Katara warned him not to open it. He would ask why he was not allowed to go outside, but Katara would kindly tell him that his special condition will not be accepted in a society of judgemental people.

One day, Katara went outside to buy groceries and accidentally left the door open. His nanny has not yet arrived, so being a curious kid, Tsukiro went outside.

* * *

The world was very lively and wonderful, Tsukiro wondered why Katara never let him go outside. His raven eyes widened at wonder, as he walked around the streets of the city.

Until he realized he had gone too far, and considering the fact that the little boy had his own trip for the first time, he was lost.

He walked and walked, crying in fear. He looked around for someone to help him go home, but he never knew his address though, if he could find someone who could help him.

Until he saw a young girl being bullied by older kids, tears falling from her cheeks as she was pushed by the bullies. She was slightly older than Tsukiro, she had red locks that reached towards her shoulders and she had golden eyes.

Of course, Tsukiro wanted to help her so he interfered, but considering the fact that he was as small as the little girl, he was also pushed away by the kids and started insulting him.

Until Tsukiro snapped.

Unleashing his true self to the scared bullies, his tentacles suddenly sprout forth from his small body, going to the bullies' neck in an instant, nearly strangling them to death. His now glowing eyes narrowed at the bullies, as the little girl was speechless, her golden eyes widened in shock. His tentacles were pitch black, indicating fury. His usually innocent aura become menacing, as his little teeth slowly sharpened.

"TSUKIRO-KUN, WHAT ARE YOU DOING?!"

Katara's scared voice rang through the boy's head as he finally come back to his senses, his now raven eyes widened at the scene, as tentacles retreating back to his body. His eyes slowly filled with tears, as he scanned the area. Katara was looking at him with shock, as his nanny gasped. The bullies, now being released from his grip, screamed loudly in fear and called him a freak, before running away. The girl he had saved was speechless, as she was also scared at the boy.

Tsukiro had felt the worst feeling of his life: intense feeling of fear. He had nearly killed a person, he nearly murdered one.

He is a monster...

He looked at his scared 'mother', who was looking at him with tear striken eyes full of concern, then at the girl, who was scared at him.

He is a monster...

He did one thing: he had hyperventilated, his breaths suddenly went quicker as flashes of what happened flashed between his eyes, his body froze in place, his head became lighter, as his vision suddenly went black.

Before he fainted, he felt the warm arms of Katara holding his fallen body as she lifted him up.

* * *

Katara had revealed to him on his seventh birthday that she was not actually his real mother, but more like his surrogate mother that gives birth to him when his biological mother is not capable to carry the pregnancy.

She also told him that even though his biological parents were dead, he still had relatives on his biological mother's side, and she planned to give him to them because it was the right thing to do.

She was now tired of hiding the little boy from the world.

Clutching the phone she was holding, she typed the number of the office of the Ministry of Defense, and dialed it, as she looked at the little 7 year old boy in front of her, looking at her with his raven eyes.

Oh, how she is going to miss this little boy.

* * *

The door opened, making Tsukiro snapped out of his thoughts as he looked at the one who entered the room.

It ws stern-looking man, his jet-black hair styled up, his piercing raven eyes stared at Tsukiro, making the child in question uncomfortable. The man was wearing a black suit with a black necktie, wearing black shoes. He looks like a professional with his suit. He was holding a folder containing a lot of important documents inside.

The man went to the desk and proceeded to sit on the chair, as his left hand picked the strewn papers on the desk then placed it aside, then placed the folder and opened it. His raven eyes was scanning the folder, humming before closing the file.

Tsukiro tried his best not to feel uncomfortable, he has to look dignified as a first impression. He don't want anyone look at him as a clumsy undignified freak who looks like crap.

The man sighed as he spoke in a voice that made Tsukiro flinch, "So your name is Yukimura Tsukiro, right?"

Tsukiro nodded quickly, trying to look down in embarrassment.

The man continued, as his voice softened a bit, as if sensing Tsukiro's uncomfort gaze, "My name is Karasuma Tadaomi, one of the commanders, especially I am the Chief Intelligence of the Ministry of Defense. And if you ask why I was assigned to handle your situation, it was because I personally knew your father."

Tsukiro perked up, as he pushed his spectacles back into place, "You know my father?"

The man, now known to Tsukiro as Karasuma-san, nodded, "We became colleagues 7 years ago, in a school not far from here, before he died. But first, do you want juice or water?"

Tsukiro smiled a bit, as he waved his hand dismissingly, " No need, I will be just fine."

Karasuma hummed, "According to this file, you apparently had tentacles."

Tsukiro slowly nodded in shame, as a silver-yellow tentacle sprouted on his head to prove a point. He expected the stern man to be surprised on how an innocent-looking child has a dark secret, but he did not expect the man just stared at it like it was nothing.

"Just like that damn octopus," Karasuma muttered to himself, but Tsukiro can hear it clearly. Because of his condition, his ears are kinda sharp and sensitive, so he can hear sounds that can never be perceived by a normal human.

Tsukiro did not comment, as he retracted back his tentacle.

Suddenly, the door opened and a woman went inside, along with a little girl bouncing behind her. The woman has long blond hair tied to a bun, has pretty blue eyes, and wearing a white polo shirt and black pencil skirt. Tsukiro could infer she was not Japanese, because her looks look Caucasian.

The girl behind him looks like she was slightly younger than Tsukiro, and she was like a spliting image of the woman, without the dark locks tied into pigtails. She was wearing a blue kindergarten uniform, yellow hat and black shoes, a moon shaped nametag was pinned on her uniform. The kanji of the name _Aimi_ was imprinted on the tag.

"Daddy!" The little girl happily spoke, as she rushed to Karasuma-san and hugged him tight. The woman, who Tsukiro infer that she is Karasuma-san's wife, smiled and spoke, "I fetched Aimi-chan from the daycare after I had a break, so I went here after that. I hope you wouldn't mind, anata."

Karasuma smiled at the child, then stared at his wife, "Well, I would not mind, Irina. I am glad I am now seeing my daughter right now, " he then asked the child, "How was school today, Aimi-chan?"

Aimi grinned brightly as she replied, "I got a star because Sensei likes how I color the shapes!"

Karasuma smiled as he spoke, "Oh really? That is great!"

Irina laughed as she went to sit on her husband's desk, "Of course, your daughter is a genius and a beautiful girl, in fact she is a natural charmer! Do you see how her male classmates fawned over her?"

Karasuma rubbed the bridge of his nose, "Irina... Aimi-chan is still a child."

Irina shrugged, "It is better to start young, she has a potential!"

As the couple were arguing over their daughter, Aimi noticed a boy sitting on the couch located on the corner, looking at the couple and her with sad eyes. The boy was a little older than her, with raven shaggy locks reaching his nape. His huge glasses were resting on his nose, complementing his kind raven eyes tinged with orange. What's weird about this boy is he has something on his neck, it was like a metal neckbrace. Aimi cocked her head in interest, as she started to approach the boy.

The boy noticed her approaching and felt uncomfortable in his seat, his hands fidgeting as he tried to look away.

"Hello," Aimi greeted the boy as she waved.

The boy stared at the girl shyly and replied with a soft voice, "Hello."

Aimi grinned as she reached out her right hand, expecting a handshake, "I am Karasuma Aimi, and I am 5 years old. What's your name?"

The boy looked up as his eyes meet hers, his hand shyly reached the girl's hand and shook it, "Tsu-tsukiro. My name is Yukimura Tsukiro."

Aimi cocked her head to the side as she flashed the brightest smile Tsukiro has ever seen, making Tsukiro smile a bit.

"You're cute," Aimi commented, as she looked at Tsukiro up and down, "You must be older than me, right?"

Tsukiro shyly nodded, "I am actually seven."

Aimi clapped her hands as she sat down besides Tsukiro, "Well, I thimk we will be good friends from now on!"

Tsukiro stared at her in surprise, "Friends?"

Aimi bumped her arm on Tsukiro's shoulder playfully as she batted her eyelashes on him, "Of course, Tsukiro-kun! Can I call you that? We are friends now!"

Tsukiro blushed as he looked away, "It could be nice."

Aimi grinned as she suddenly hugged the blushing boy, "We are friends now!"

Irina stopped arguing with her husband when she noticed Aimi hugging the little boy on the corner of the room, her blue eyes clouded in confusion, "Anata, who is that boy?" she asked her husband, a little malice on her honey voice. Karasuma sighed as he gave the file to Irina, giving her a pointed stare. Irina stared at her husband, cocking her eyebrow as she opened the file. She scanned the contents of the file, as her baby blue eyes widened at every passing second.

"No way," she gaped as she looked at the boy in disbelief.

Karasuma grimly nodded, "I am afraid it is the case."

Irina lowered the file down as her sweet voice lowered to a whisper, "So he is the octopus' son? He is too young!"

"Yes, he was. But we can't deny he is the child of the octopus, you read his file, " Karasuma confirmed it to her.

Irina shook her head in disbelief, "I can't believe this actually happened. If Koro-sensei's alive, he would not take this news too lightly, you know. By the way, did you call the brats? If the octopus was involved again, that means they should know about this."

Karasuma nodded, "I had called Nagisa-kun first about this, we will meet at the classroom later, along with Kayano-san. I also called Isogai-kun too, announcing that their plans about fixing the classroom will be rescheduled tomorrow. I already explained to them the situation and Isogai-kun said they all agree."

Irina hummed, "It make sense Nagisa-kun and Kayano-san will be coming first, considering the fact that Kayano-san and Yukimura Aguri-san were sisters, and Nagisa-kun is the one who stabbed Koro-sensei."

Karasuma sat at his chair once again, crossing his arms as he stared at his child interacting with the boy, Irina was smiling at the two.

"Can we come with you, anata? I mean, I am also their teacher, you know," Irina asked her husband, as Karasuma sighed.

"Fine, you could come with us, take Aimi-chan too. I wanted her to see her dear Nagisa-oniichan and Akari-oneechan afrer all."

* * *

It was a long trek to the hill where the Class E building stood, as the Karasuma family and Tsukiro were catching their breaths, tired from the journey up. The former Class E classroom was a beautiful sight, as the nature was thriving on the place. The former field where they conduct their PE class was now overgrown with grass, as the building itself was still old and unused. The air was refreshing as it blew gently, ruffling Tsukiro's raven locks.

Tsukiro and Aimi was amazed on the sight, as Irina sputtered for breath. After all, she still did not like climbing up the hill, as like before.

"Welcome to the former Class E building," Karasuma spoke as they approached the building. Tsukiro looked around the place, his raven eyes sparkled in wonder.

"This is where I, my wife and your father taught seven years ago," Karasuma continued, as Tsukiro widened his eyes at what the man had said.

"My father is a teacher?" Tsukiro asked, as Aimi was bouncing happily and adoring the flowers growing on the grass.

"The best," Irina answered, as she held her husband's hand, "He was dedicated on his work, in fact he will do anything, even turning the world upside down just to teach children."

Tsukiro was awed. He never knew his father, but according to what the couple said, he must be amazing.

"What are we waiting, Mommy?" Aimi's voice perked up.

"Not what, dear, who. We are waiting for someone, dear, I am sure they are coming here right now, so behave okay?" Irina reminded her daughter, "That includes you too, Tsukiro-kun."

"Yes, mommy," Aimi chirped as Tsukiro nodded.

"Here they are," Karasuma pointed out the two figures approaching them as they went to the old building. It was a man and a woman, the man has blue hair that reached his nape, wearing a blue vest under a white polo shirt, grey pants and black shoes. His eyes were a bright blue, like the ocean. The woman has long black curly tresses that reaches her hips, with beautiful hazel eyes. She was wearing a red dress and black flats. She was pretty, Tsukiro noted, but he could feel a comforting aura around her.

Aimi brightened, as she recognized the two, they were her godparents after all. Well one of the 28 godparents she had, of course.

It was Shiota Nagisa and Yukimura Akari.

* * *

**_A/N: So this is what happened during Chapter Two, after Karasuma called Nagisa, and before Chapter Three!_**

**_So_****_rry for the long wait, it has been long since I updated this one, well, this time is one of the times I got internet access, and I am busy with my online classes right now, so..._**

**_This is now where Aimi and Tsukiro first met! This was actually different from what I originally planned, as the original plan is they will meet at the old class shed, the shed where Kaede had revealed to Koro-sensei her real identity. As you can know, the main OTP will be them._**

**_There will be canon pairing like KarasumaxIrina, NagisaxKaede, KarmaxManami, etc. And Nagisa and Karma are only bestfriends, more like brotherly bond. I respect yaoi, but I support canon-based pairing though!_**

**_I will be posting some TSCCM related fanarts on my Tumblr! Search for Alithea Korogane, that is my name in Tumblr,_**

**_D_****_on't forget to review, like and follow! I am greatly appreciated if you do_****_. Reviews are encouragement to do better andto improve! No flames though, constructive crititism are nice._**

**_With love and tentacles,_**

**_A_****_lithea Korogane_**


	5. Akari Yukimura's New Role

_The Karasumas looked at each other before turning their heads to their former students, Tadaomi sighed deeply as he spoke, "I forgot to tell you but...Tsukiro-kun is not the only child created by Yanagisawa Kotarou."_

_Akari and Nagisa's eyes widened in shock._

_"In fact, he created another child. His own child."_

* * *

Yukimura Akari couldn't believe what she had heard.

Seven years ago, her sister Aguri had died. It was the worse day of Akari's life. Her sister was the only family she had besides her absentee father, as her mother died because of an illness. After her mother's death, her father's treatment over his daughters had changed, he became heartbroken and started to couldn't take care of them. That is when Aguri started to take the reigns and support her little sister, who became a budding child actress at that time.

Akari loved her older sister with all her heart. She loves how she smiles whether problems started to appear, and she likes to support her sister, no matter what Akari would choose to be.

She kinda admit, she was jealous of Aguri in terms of genetic department. Although her appearance was somewhat plain, with short black hair and dark eyes tinged with orange hues, Aguri had a massive chest, which Akari would want to have. Aguri was also tall for a woman her age, compared to Akari who inherited their mother's short stature.

Akari hated Yanagisawa the first time when he was introduced by her father as Aguri's fiancé. As an actress, she knew how to read emotions of a person, and she could see Yanagisawa's smile being forced as he smiled at Akari and Aguri. Aguri, too, was smiling, but the smile doesn't reach her sad eyes. That is when Akari realized that her sister doesn't love the man. She was only forced to marry Yanagisawa, as their family business, a pharmaceutical company, merged business with Yanagisawa's. Her sister Aguri was just a collateral.

She saw her sister became depressed as years went by, even though Aguri never shows her sadness to other people, hiding her sorrows within a smile and her cheerful personality. Yanagisawa made Aguri work for him, while Aguri balancing her new work with her teaching career. She could see dark circles on Aguri's onyx eyes, as she only had to sleep for a few hours. She could hear her sister crying every night, even though Aguri shrugged it off, saying she was not crying.

One day, she noticed her sister finally became happy. Her sunken eyes twinkled, as her smiles were getting genuine as ever, compared before. She sometimes hummed some cheerful songs while she cooked for her sister, and what's weird, it seems that Aguri finally looked forward going to Yanagisawa's lab with a smile on her face. Akari knew that look.

Aguri had finally fallen in love.

Akari prayed it was not Yanagisawa. That devil was not right for her sister. Turns out it was someone else who made her sister look like that way.

One day, she noticed a gift box on her sister's bag, when Aguri was out. She opened the box with curiosity, thinking if Aguri was planning to give it to someone.

It was a huge black necktie.

Akari sighed and rolled her hazel eyes, smiling. She knew her sister's fashion choices, it was terrible. She wondered if the recipient of the gift would wear that, the necktie looks dorky. At least, Akari knew that her sister had found someone who made her happy. Hoping that she would stay like that forever.

Until one day.

She became devastated when her sister died. She had witnessed her sister lying lifeless on the arms of her future teacher, Koro-sensei. At that time, she thought Koro-sensei killed Aguri at first, so she made one of the greatest mistakes of her life. She had injected tentacles on her nape, for revenge. She pretended to be someone else, to be a meek-looking green-haired Kaede Kayano. The pudding lover. The innocent one. The bystander.

Turns out it was a bad idea.

She risked her life for revenge. She bore the pain of the tentacles, thinking ways to kill the murderer who killed her sister. For a year, she only focused on revenge. Her tentacles fought with Koro-sensei, with her trying to hold on what her sanity had left. She nearly died, for her revenge. She was starting to regret her decision as her sanity slowly fading away, letting the tentacles and their whispering hold her entire soul.

Until Nagisa kissed her right on the lips, his tongue melding with hers, as she was pulled back to the surface. (And she was still blushing when she thought about that day.)

Until Koro-sensei had revealed everything. The truth she was waiting for all this time. And Akari could only see the necktie hanging on Koro-sensei's neck with a sad realizing look in her face, while it was fluttering lazily in the wind, mocking her.

Aguri was falling in love... With Koro-sensei.

The man who had made Aguri happy before she died.

So it is time to repay the debt.

She sacrificed everything for everyone.

Koro-sensei, the teacher who truly loved her sister and fulfilled his promise to her by taking care of Aguri's class. For her sister, the one she really cared and loved, who had supported her in any way . For Nagisa, who became her real friend and the one Akari had started to love. For her classmates, the one who accepted her despite everything.

She took the blow, her blood sprayed to the cold hard ground, just to save Koro-sensei time to recover. She smiled, as she was looking at the moon above, before she closed her eyes.

But turns out, Koro-sensei saved her instead, bringing her back to life. Kayano thought there will be happy ending, but turns out that at the end of the story, he still died on their arms.

Koro-sensei was now reunited with Aguri, as their souls and strings entwined to each other, as they walked in the afterlife. Akari smiled despite the tears in her eyes. At least, she knew that their story had a happy ending at least, although laced with tragedy.

Akari thought that their love story ends with Koro-sensei dying on their arms and reuniting with Aguri in the afterlife.

Turns out it was not yet done.

* * *

"I can't believe that man made two children out of unethical means," Akari said out of spite, "Using my sister as his guinea pig. After all, he had crossed a line when he used Koro-sensei as a guinea pig for his crazy experiments. I still wonder why the government still funded his research at that time. No offense, Karasuma-san."

Karasuma nodded, "None taken. Sometimes the government has to sacrifice dignity for publicity and progress. Or for the sake of the world. Sometimes it backfires, causing more trouble on the citizens."

Nagisa comforted the distressed actress, "But at least, we now know about their existence, and of course, we knew Tsukiro-kun was now safe."

"But what about the other one? As much as I hate the fact that she was the daughter of that..._monster_, she is still my little niece. She is still Aguri-neechan's child. Any news about her? Is she safe?" Akari asked Tadaomi, her golden eyes etched in worry.

The military man sighed as his head lowered, speaking in a sad voice, "Unfortunately, we had no news about the kid. Yanagisawa Katara-san never told us about the issue, but according to her written statements, she had escaped with newborn Tsukiro-kun when the octopus' assassination incident happened 7 years ago, along with her co-worker and the newborn female, but her co-worker was caught along with the girl when they try to escape. Katara-san escaped with the boy, and according to her, she was still in recovery from giving birth to them days prior."

Irina gave a look of pity, her hand touched her husband's shoulder, "Giving birth was not easy, you know. It took me weeks to recover and work after giving birth to Aimi-chan."

"Also, she was in the vinicity of the mountain when we assassinated the octopus," Karasuma continued, earning the shocked looks of the two young adults in front of him.

"What?! But we never seen her while we went to infiltrate the mountain to get to Koro-sensei!" Akari exclaimed, while Nagisa nodded in agreement.

"But she did. She went after you had infiltrated, holding the newborn boy in her arms. Unfortunately, she can't go forward to your location," Karasuma grimly spoke.

"Why she can't go forward and go to Koro-sensei? He was Tsukiro-kun's father, Sensei deserved to know about his little child!" Akari stressed out, her hazel eyes narrowed.

Being a perceptive person as he is, Nagisa realized too quickly. He remembered what Karasuma-sensei had told about Tsukiro earlier. Closing his azure eyes, he sighed as he spilled the beans.

"Tsukiro-kun can't."

Akari looked at her bluehaired companion, her voice faltered in confusion. Nagisa opened his eyes, stared at Tsukiro, who was playing with Aimi, with a pitiful expression, then looked at their former sensei.

"If we remember what you said, Sensei, Tsukiro-kun apparently had inherited some of the abilities that Koro-sensei had. More likely, he can conjure tentacles from any part of his body. Tsukiro-kun's condition is more advanced than the tentacle implants that Kayano and Itona had before, but less advanced than the Koro-sensei's. And as the file and you had said before, Tsukiro-kun's tentacles can't be easily removed, for the antimatter particles is already grafted in his DNA, isn't that right, Karasuma-sensei? " Nagisa explained thoroughly, as Karasuma nodded in response.

Nagisa held his chin in thought before his gaze went to Akari's hazel orbs, "Do you remember what could damage Koro-sensei?"

Akari's hazel eyes widened in realization, her voice hushed in a whisper, "Anti-Sensei material... That barrier that trapped Sensei was made using that material too."

Nagisa nodded, "Considering the fact that Tsukiro-kun has antimatter cells grafted to him, of course he will be affected by the barrier. Likely, he would also be disintegrated by the laser."

"Of course, the woman would have common sense not to let the boy come in the barrier. It would be risky," Irina spoke, shrugging. Her blonde locks swayed slightly in the wind, as she looked at the two children not far from them.

Tadaomi looked above, remembering that fateful day. "Nagisa is right. Katara-san wanted to enter the barrier to get across and meet the octopus, but she failed after realizing how the anti-octopus barrier affected the child. And considering the fact that the octopus may be dead at the end of the night, leading the child to be imprisoned by the authorities once the news of the child's existence comes out, she decided to raise the child away, for seven years. She was also consumed by guilt from leaving the female newborn behind too, that is why she is dedicated to keep the boy safe."

Akari and Nagisa's gazes went to the little black haired boy playing with Aimi on the grass. Aimi was talking to him, smiling brightly as she held Tsukiro's hands with hers, her fingers intertwined with Tsukiro's fingers. Tsukiro's cheeks was blushing pink, looking at Aimi with a surprised look, as Akari could notice that the boy's hands twitch a little, acting like Koro-sensei's tentacles. It seems like Tsukiro was trying to repress his hands from slithering too much, trying not to scare the little five-year old girl in front of him.

Akari smiled sadly at the scene, while Nagisa patted the woman's back, comforting her. The Karasumas looked at the children with a wistful look, as they saw their little princess interacting with the little human-octopus hybrid.

Akari thought of her sister. Maybe this is her second chance on making her sister amd Koro-sensei happy.

Her new role. This time, it will last until the end of her days. This is not the same with her roles on TV or movies, this is real-life.

And this huge role also had a huge responsibility to uphold. And she will do everything she can to fulfill it.

She turned at the Karasumas as her eyes was filled with determination.

"So... If this is our new mission as students of Koro-sensei, I will accept the challenge. Now, can I have my beloved nephew staying with me?"

Nagisa and the Karasumas look at Akari with a bewildered look.

"But what about your work as an actress? Would it be difficult to take care of not only a child, but with tentacle cells grafted in him, while doing your acting career?" Nagisa asked the ravenhaired girl in worry.

Akari shrugged, "After all, I am a former tentacle user, I can train him to use his tentacles for good. You had no choice on the matter, it is rather me or Itona-kun, which is not related to Tsukiro-kun by blood. I can get used to it, I am an versatile actress, and I can my balance my life as an actress and a supportive aunt. Think of it as my new project, as my role. I will be his guiding aunt. Besides, I wanted to make my sister happy, and what better way to do it by raising her darling son into a respected individual?"

The Karasumas and Nagisa look at each other before looking at Akari who smiled. Tadaomi sighed as Irina smiled sweetly, "Well, let's get the mission started, shall we?"

* * *

**_A/N: And the chapter stops here... For now._**

**_After months of inactivity for this story, I finally had a chapter to update._****_This was actually longer, but I decided to cut it into two chapters, for it already reached 3k words if I hadn't cut it. Talk about not stopping._**

**_In this chapter, we could see Akari/Kayano's point of view of the situation. As you can see, even though she seems to be moving on from Aguri's death, she still missed her sister a lot. It is not easy to let go of the ones you love, but little by little, wounds of grief have started to heal with the ones who loved her. The E-Class help her cope with it, and with the arrival of her unexpected gift, her nephew Tsukiro-kun, she will finally learn to be happy._**

**_I took longer to update this because I have started to become busier these days. Online classes are starting to get to my nerves so... Stress takes over._**

**_And while I lost some ideas to throw for this story, I had drawn some random TSCCM fan arts on my Facebook, Instagram and Tumblr account, featuring Tsukiro and Aimi as young adults. Talk about productivity. Hahahaha_**

**_Don't forget to review and favorite!_**


	6. The Start of a Beautiful Friendship

**_While the adults are talking about Tsukiro's situation..._**

"So, Tsukiro-kun, where do you came from? Where did you study?" The dark haired girl asked with a toothy smile, as her blue eyes sparkled. Tsukiro, whose cheeks was blushing red as a tomato, stuttered, "Um... I just live ne-near here. And I ne-never we-went to school. I was homeschooled..."

"Oh! So you never had any friends before?" Aimi curiously asked the boy, while looking at him. Tsukiro shook his head slowly.

"So I was your first friend?" Aimi asked, her eyes widened in happiness on the prospect of being Tsukiro's possible first friend. Tsukiro saw the sparkles on Aimi's eyes and couldn't help but to smile at her antics, nodding his head in response. And it was true, Aimi was Tsukiro-kun's first friend. He was never allowed to go out back then, therefore he had never met anyone ever since the incident.

Aimi squealed in happiness as she jumped up and down, and quickly holding the boy's hands with hers. Tsukiro blushed when he saw what Aimi was doing, his hands was slightly bending and slithering. He cursed mentally as he tried to quell his slithering hands, afraid that Aimi would notice them and be scared of him.

His silent prayers went unanswered though.

"Woah...Are your hands moving?" Aimi looked at Tsukiro's hands intertwined with hers, emotions of awe struck in her angelic face. Tsukiro's dark orbs widened in fear, as he flinched and quickly started to pull his hands away, trying to hide it behind him. "Um... No?" Tsukiro tried to reason convincingly, but his voice betrayed him.

Aimi noticed what Tsukiro was supposed to do, so she tightly held Tsukiro's hands with hers and saw his hands stretching and bending in inhuman ways, wrapping in her hands. Her eyes widened in surprise, before she stared at them in awe. "It really was!" She exclaimed, staring at the boy's moving hands.

Tsukiro flinched, as he forced to pull his hands back and hid it behind him, looking down in shame. His young mind reeled in millions of possibilities, thinking that Aimi may be scared of him. Memories of that fateful incident echoed in his mind.

_I am a monster. A monster._

Aimi's hands are still on the air as Tsukiro pulled his hands back, staring at Tsukiro in awe. She then stared at her hands and started to close and open them, as if testing them. "I can't even do that. How can you even do it, Tsukiro-kun?" She asked in a curious tone.

_A monster. No one will accept you. _

Tsukiro's head was still bowing down, his hands was still behind him. His huge glasses started to become askew, nearly on the brink of falling, as his dark orbs scanned the grass below him. He never replied to Aimi's question.

Aimi reached Tsukiro's face and grabbed his glasses, making Tsukiro looked back at the girl in shock, his dark orbs shining in the sunlight, their yellowish orange tint was showing clear in the sunlight. Aimi stared at the huge specs in her hands and to Tsukiro's glassless face, "Your nerdy things nearly fell out of your face. You know, you look cute without these nerdy things, but daddy said some people needed them to see."

Aimi proceeds to wear Tsukiro's eyeglasses out of curiosity and squinted, before removing them in a haste, as a growing headache was felt, "My head and eyes hurt," she moaned in pain, as she rubbed her baby blue eyes to ease the pain. Tsukiro suddenly grabbed her hands in concern, his slithering fingers wrapping on Aimi's dainty hands. Aimi looked at Tsukiro in surprise, her sparkling blue eyes puffy from irritation.

"I-I th-think you should never do-do that. It will make y-your eyes hurt more," he stuttered in concern, as his dark orbs stared at Aimi's blue ones. He then squinted at her face, his face scrunched in concentration, as everything was blurry to him. Aimi raised her eyebrow at Tsukiro's expression, as she laughed.

"What are you making that face?" Aimi asked between laughs, as Tsukiro blushed in response, pulling his hands away from her and sputtering words such as, "Not my fault my vision was blurry" and "I can't see clearly".

"I-it's just that I can't s-see things clearly. Ca-can I have my glasses back?" He pleads to Aimi, pouting and blushing as red as a tomato.

It was strange for someone who had accelerated healing and antimatter-infused cells to have faulty vision, but Tsukiro was unfortunate to have one. It seems that his antimatter-saturated body can't afford to heal his poor vision, and Yanagisawa Katara had theorized that it was probably a miscalculation on her brother's part, genetics (probably had a recessive gene inherited from pre-octopus Koro-sensei or Yukimura Aguri that Kotarou never noticed and fixed), or side effects of the experiments.

She felt pity and started to place Tsukiro's glasses back to his eyes, as she smiled brightly, "Besides, I think your hands look cute."

"C-cute?" Tsukiro thought to himself, as he blushed like a red tomato. His hands was slithering behind his, bending and stretching beyoung human capabilities, showing how Tsukiro was feeling.

Aimi laughed at Tsukiro's blushing face, as she continued to speak, "Of course! Those look like octopus' tentacles, and I love octopi! I had a octopus plush at home, Daddy gave it to me. It was yellow and cute! Daddy said to take care of it because it was given to him by someone. "

"I asked Mommy who it was, and she said that a close friend of them gave my octopus plush as a gift for me. She also said that close friend is an actual octopus, like the plush. She said he was like us before, a grown-up adult like daddy and mommy, and he was bad, until he was cursed to be an octopus by a mad wizard."

Tsukiro looked at Aimi in confusion, as he wondered why Aimi would tell him a fairy tale story. _Did she really compare me with an octopus? Seriously?_ _And a huge octopus? _

"The wizard has a hostage, a princess. She and the octopus are close friends, mommy said the octopus fell in love with her, but the mad wizard is angry. He tried to kill the octopus, but the octopus had fought with all his power and became angry, destroying everything he went. The mad wizard had unleashed a spell to kill the octopus but he made a great mistake instead of killing the octopus."

Aimi looked above at the skies, staring at the small moon showing in the afternoon skies. The moon was small, but Aimi was told that the moon was not as small before as it was in today.

"Mommy said that the mad wizard had caused the moon to be small. The moon was not small before, Daddy told me. I also saw pictures of the moon many years ago. The real reason is, the evil wizard broke the moon, and also killed the princess. Before the princess died, she made the octopus promise to take care of children the princess wanted to take care of, she also said that maybe that promise could break the curse. The octopus loved the princess very much, so he took care of the children the princess had loved."

"Mommy called the children brats and little shits though. But daddy would be angry and scold mommy for that." Aimi continued. Tsukiro couldn't help but smile a little, trying to contain his chuckle. His 'mother' would sometimes curse on accident in front of him. He never knew the innocent-looking Aimi would use curse words. But then, he had expected Aimi's mother to spew offensive words though.

"Mommy said that she first hated the octopus when they first met. She said the octopus was a creep and a perv. Daddy had scolded Mommy for that, but Mommy said it was true."

Tsukiro laughed at what Aimi had said, as Aimi continued, "The wizard always tried to eliminate the octopus with all he can, but the octopus was still hard to kill. The children starts to love him too. Months later, the kingdoms who wanted to kill the octopus decided to build a trap, and it worked. The octopus was trapped. Then the wizard brought a monster as powerful as the octopus, so that monster could finally kill the octopus. That monster was also cursed by the wizard, and he was the octopus' former pupil."

Her hands was also moving to explain how the events on the tale transpired, as Tsukiro was listening attentively on the tale. Tsukiro felt that the story was familiar, although he couldn't place where he had heard it.

"They fought, and fought, as the octopus was losing. The monster was too strong. Until one girl decided to join the battle and protect the octopus. She died though," Aimi spoke in a sad voice.

Tsukiro looked at Aimi, disturbed at what he had heard. How this was a child-friendly fairy tale? His "mother" would tell him stories with happy endings, not what Aimi had narrated. Someone died on a fairy tale of hers. (**_A/N_: _Can some tell Tsukiro-kun that there are dark fairytales that had someone died? Even Disney classics like Cinderella have darker versions._**)

Aimi noticed the disturbed look on the boy's face so she quickly added, "Well, Mommy said she lived after the octopus healed her. That was after the octopus defeated the monster who killed the girl, it goes boom!" She waved her hands to imitate an explosion.

Tsukiro smiled before he asked, "Then what happened... Next?"

Aimi stared at Tsukiro with a sad look, "Mommy said the octopus was tired, and he couldn't escape the trap. At the end, he died at the arms of the kids he loved, Mommy and Daddy saw it all."

Aimi smiled brightly, "But Mommy had assured me that the octopus would guide all of us, even he is now in heaven with the princess!"

Tsukiro looked at Aimi, his eyebrow raised in confusion. The story is kind dark in his opinion. And for a 5 year old to be told about these things... It was disturbing.

He started to open his mouth when Aimi-chan's father called," Come here, Aimi-chan, Yukimura-kun!"

Aimi brushed the dirt on her uniform as she replied, "Yes, Daddy! Come on, Tsukiro-kun!"

Aimi held Tsukiro's hand and dragged him to her parents' location, as Tsukiro followed her with a blush on his face. His hands slithered once again in embarrassment, as he looked at the girl holding his hand. Aimi paid no mind on the moving hand and just keep going.

The two of them went to the four adults, looking at them. Tsukiro stared at the young adult woman infront of him, smiling at him as her brown locks were flowing to the wind. She was smiling at him, her hazel eyes sparkling. Her blue-haired companion was holding the brunette's shoulder in comfort.

Tsukiro could deduce that the woman was her early 20s, noting her young looks. And she looks kind of similar... To the woman in the photo Katara was showing him when she had revealed to him that Katara is not really Tsukiro's biological mother.

* * *

_"I am not your real mother."_

_7-year old Yukimura Tsukiro __can't believe his ears._

_"What you mean, Mommy?" He asked curiously, his huge dark orbs staring at Katara._

_Katara kneeled in front of the kid, so Tsukiro could see her lime green eyes, and looked at him with sad eyes, "Sweetie, listen. I'm sorry, but it is time for you to know the whole truth.__ You are a big boy now, and you are seven." _

_Then she smiled sadly. __"Can you just wait here, I have to fetch something on the room," Katara softly instructed Tsukiro, who replied, "Yes, mommy."_

_Katara went to the room for a few minutes before she came out of the room, holding a photograph. Tsukiro cocked his head sideways in curiosity._

_Katara went to the sofa and patted beside her, motioning for Tsukiro to sit beside her. As an obedient boy he was, he sat down quietly._

_The female scientist hesitated before gave the photograph to Tsukiro with gentleness. Tsukiro got it and inspected the photograph, it shows a short haired woman wearing a weird t-shirt and blue skirt under a lab coat. She was smiling sweetly, her dark orbs similar to Tsukiro was shining brightly at the camera. She has a huge chest though, Tsukiro had noticed._

_"Her name is Yukimura Aguri," Katara explained softly at the curious wide-eyed boy, "She is your real mother. The reason why your surname is Yukimura is not because you had your father's surname, it was your mother's."_

_"She is my real mama?" Tsukiro spoke, caressing the photograph with his fingers. Little strands of tentacles were starting to appear, wriggling slowly in his head, casting a soft glow. Tsukiro usually__ releases those little tentacles whenever he is stressed._

_Katara nodded._ _Tsukiro's dark eyes started to tear up, as he was looking at Katara, who was starting to tear up too, "Where is she, mommy? Why did she...leave me? Does she hate me? Because I have tentacles?"_

_"No!" Katara shook her head in alarm, as she was smiling gravely, "She loved you, dear. It is just...she was now in heaven."_

_"Oh," Tsukiro felt disappointed. "Do you know who my papa is too?"_

_Katara nodded, as she wiped Tsukiro's tears, "He was also in heaven, dear."_

_Tsukiro's tears started to fall as he had found out his real heritage. His 'mother' was not his real mother, and his real parents are dead, he will never see them in his life._

_Katara looked at the crying boy in pity, so she held Tsukiro's chin gently, aligning his dark orbs to her green ones, "I am sure that they are watching over you, sweetie. And they are proud of you. Besides, I am here to love you with all my heart."_

_Katara hugged the crying boy , until he fell asleep on her arms. _

* * *

"Hi, Tsukiro-kun," the brown-haired woman waved at him, as Tsukiro just stood there, staring at her.

"By the way, Yukimura-kun, this is Yukimura Akari, your mother's sister. That makes her your aunt," Tadaomi introduced the woman, who was now named Akari.

_That's why she looks similar to Mama, she is Mama's sister, _Tsukiro thought to himself, as Akari kneeled down, a sweet smile in her lips.

"Yes, I am your auntie Akari. You can call me that, Auntie Akari. That has a nice ring to it," Akari spoke gently, as she held out her hand, "Nice to meet you!"

Tsukiro looked at Akari's hand and hesitated to hold it, but he slowly raised his hand and shook it, making the brown-haired woman smile. His hands slithered in nervousness, as he had the urge to release those little tentacles again, but he was scared for the two people in front of him to know his secret. But the woman paid no mind on his slithering hands, she just hold them with tenderness.

"Don't worry, I know your secret, dear little octopus," Akari added in a playful tone as she winked playfully, making Tsukiro widened his dark orbs in shock.

"And I am Shiota Nagisa, Kayano's friend," the blue-haired feminine man beside Akari spoke softly. "Don't worry, I won't judge you because you have tentacles. I have gotten used to see them in the past with someone I know." He chuckled at the last part.

Tsukiro cocked his head in confusion, "Kayano? I thought her name is Akari."

Akari looked at Nagisa with an eyebrow raised, while Nagisa waved his hands sheepishly, "Um, I call Akari-san as Kayano because she was known to us as Kayano Kaede. But that is a story for another time."

Tsukiro raised an eyebrow, "Okay?"

Tadaomi coughed to gain their attention, and spoke in his usual deep voice, "Well, we wanted to know if you are capable of taking care of the boy, Kayano -san. Considering the fact that you have a busy schedule, I am worried that you will never take care of him."

"I remember you had said that you had a party to attend to at 8 pm?" Nagisa pointed it out.

Akari shrugged as she smirked, "Well, I could just call my manager and say that I had a family emergency. Family is first."

"Anata, Kayano-san would be fine! She is now a capable young lady. If the octopus was here, he would approve of this, " Irina scolded her husband, as she held Aimi's hand.

"Besides, this is a new mission of Class E, right? If you want, we could call some old buddies from Class E to babysit our sensei's baby boy. They are going to be here tomorrow, right?" Akari spoke with a playful tone, but the adults feel that there is an edge on it.

"Fine, Kayano-san. But call us if you need help, it is still our responsibility as your teachers after all," Tadaomi clarified.

Irina smiled sweetly, as she held Aimi's shoulders, who was trying to free from her mother's grasp, "Besides, Tsukiro-kun will be a good playmate for our Aimi-chan, don't you think? But, if he dares to be a perv to my daughter like how his father was, I will make sure he will lose more than one tentacle."

Her voice was dripping with malice, making Tsukiro shiver in fear. Akari and Nagisa laughed sheepishly, while Karasuma rubbed the bridge of his nose in frustration, "Irina, no violence in front of the kids."

Tsukiro's life has started to get a little more interesting.

* * *

**_A/N: Finally, a new update for this fanfic!_****_This was getting longer, so I had stopped here. Currently, I am very busy with online classes so I had little time to update a new chapter. And writer's block started to attack me at all sides._**

**_Here is another fluffy chapter featuring little Tsukiro and Aimi! I have fun writing interactions with these two, but it was hard to keep their personalities intact. Their personalities are polar opposites, as Aimi was an optimistic and cheerful girl who was very friendly, while Tsukiro was a shy boy who is still struggling to come out of his shell._**

**_Did the fairy tale story Aimi had narrated familiar to you? Yes, Irina had apparently told Aimi the story of Koro-sensei! And apparently the one who gave Karasuma an octopus plush was Koro-sensei himself back then, along with the graduation book and the guide. Koro-sensei knew that someday Tadaomi will start a family someday, and Koro-sensei wanted to give a gift to his closest colleague._**

**_And Tsukiro have eyeglasses to see, which is strange considering the fact that he has antimatter genes. Two reasons, one: I want to differentiate human Koro-sensei to Tsukiro like Superman to Clark Kent; and two: He is not giving his wish yet to the tentacles. You will found out soon._**

**_Tsukiro called Yanagisawa Katara as 'Mommy' while he called Yukimura Aguri as 'Mama'. Yes, Tsukiro is a smart kid, he quickly adjusted to the situation, although it was hard for him to accept the truth._**

**_Don't forget to fave and subscribe this story, along with my other fics!_**

**_With love and tentacles,_**

**_Alithea Korogane _**


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